Fig. 6:

Two-dimensional shear wave phase velocity image reconstructions for Model B with an SNR of 20 dB, using the proposed LPVI technique. The spatial window size was 4.5 × 4.5 mm, and selected frequencies, f₀ = 750 and 1000 Hz. Results for shear wave (a) particle displacement signal as an input signal, with inactive directional and wavenumber filters, for a single ultrasound focused push beam (SP); (b) particle velocity signal as an input signal, with inactive directional and wavenumber filters, for a single ultrasound focused push beam (SP); (c) particle displacement signal as an input signal, with active directional and wavenumber filters, for a single ultrasound focused push beam (SP); (d) particle velocity signal as an input signal, with active directional and wavenumber filters, for a single ultrasound focused push beam (SP); (e) particle displacement signal as an input signal, with active directional and wavenumber filters, for multiple ultrasound focused push beams (MP); (f) particle velocity signal as an input signal, with active directional and wavenumber filters, for multiple ultrasound focused push beams (MP). Vertical, dashed lines separate regions where the focused ultrasound push beams were located.